The Premier League is preparing to use Sulaiman Al-Fahim's takeover of Portsmouth as a test case for its strengthened fit-and-proper-persons rule that is due for introduction next week. Al-Fahim, a charismatic Dubai property investor, announced on Wednesday his intention to bid for the Fratton Park club using his "Al Fahim Asia Associates" instrument, which he described yesterday as being "structured like a closed-end private equity fund".

A source with knowledge of the deal said Al-Fahim is the owner of the fund but that it had numerous investors who had pledged their money on condition of anonymity. However that will not wash with the league, whose chief executive, Richard Scudamore, has said: "We should know and the public should know and the fans should know who owns their club."

The new rules, which will not only demand that shareholders' details are lodged with the league but that they are also made available to the public, are expected to be introduced by Gloucester Place during its annual general meeting at the end of next week. Al-Fahim's move for Portsmouth will be the first to fall under the policy. "We will work to discover who are the ultimate beneficial owners of the club," said a spokesman for the league.

Al-Fahim said: "The money for thePortsmouth FC acquisition and the needed future investment has been raised through the network of Falcon Equity from Asian and Middle Eastern investors."

Along with Pini Zahavi, the football broker, Pairoj Piempongsant assisted in finalising the deal for Portsmouth on Tuesday. Piempongsant is a senior advisor to the former prime minister of Thailand Thaksin Shinawatra and played an influential role when his countryman sold Manchester City to Sheikh Mansour last summer. This connection may be responsible for speculation in Dubai last night that Shinawatra is among Al-Fahim's backers. Al-Fahim was not available for comment last night.

What is clearer is that the acting head coach Paul Hart's potential future as the permanent manager has been put on hold until the due diligence, which will complete the deal, is carried out.

"The club cannot make any further comment on the future structure of the club until this period has been completed," a statement said. Some reports have linked Sven-Goran Eriksson as Al-Fahim's choice as manager, but it is understood that there has been no contact with the former England and Manchester City head coach.

Due diligence will commence next week amid mixed messages over how long it will last. The club believes it will take one to two weeks but a spokesman for Al-Fahim indicated it would not be completed until July. Even in the best-case scenario it will take Portsmouth past the opening of the transfer window on 1 June, casting doubt over their ability to make a slick start to any transfer business.

"Everything I have seen makes me sure that we can build a great football club in the years to come," Al-Fahim said. "Portsmouth has incredible history and its fans are some of the most loyal in the world of football. I look forward not just to working with them but listening to their views on how they want to take the club forward. I am the investor but this is their club and their community and it is a privilege to be taking charge.''